Plum met-lam p



(No Model.) s Sheets-Sheet 1.

' J. ROAGH.

PLUMMET LAMP.

No. 287,580. Pate nted Oct. 30, 1883.

INVENTQR M M M M Attorneys.

WITNESSES 3 Sheets-Sheet 2.

(No Model.)

Patented 0011 30, 1883.

WITNESSES .Altorney;

N. PYETERS. Pmlo-Lilhogmphcn Whhiugian. 0.1:.

UNIT ATE PATENT O FIC JoIIN ROAOH, or sAN FRANCISCO, CALIFORNIA.

PLUMMET-LAMR;

' SPECIFICATION forming part of Letters Patent- No. 287,580, dated October so, 1883,

' I Application filed July as, 1883. (No model.) I

To all whom, it may concern.-

Be it known that I, J OHN ROAOH, a citizen of the United States of America, residing at San Francisco, in the county of San Francisco 5 and State of California, have invented certain new and useful Improvements in Plumb-Bobs; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention has relation to improvements in plumb-bobs, and ,is especially directed to provide an instrument of the kind named to to be used in places and under'circumstances excluding the suns light; hence the object of the invention is to construct an illuminated plumb-bb, by which the line of perpendicularity may be ascertained or shownby the direction of the flame of a lamp properly protected and controlled.

In the accompanying drawings, forming a part of this specification, Figure l is a perspective View of my improved illuminated 2 plumb-bob. Fig. 2 is a view in perspective,

showing the several parts detached and relatively arranged. Fig. 3 is a central vertical sectional view, and Fig. 4 is a view showing the instrument suspended from a tripod.

The letter A represents the plumb-bob, made of metal, and of any of the usual configurations. This plumb-bob is formed with achamher, a, for containing oil or burning-fluid, and is also formed with the rim or flange b, with screw-threads on the outside and insidethereof, for the purposes about to be stated. To the inner screw-threads of the flanges b is fitted the cap B, for closing the oilchamber. This cap consists of the plate 0 and screw-threaded annulus d, of less diameter than the diameter of the plate, in order that a shoulder may be formed to rest on the rim of the flange b ofthe plumbbob .when the cap is screwed home in the plumb-bob. This cap B is also formed or provided'with the wick-holder e, which is accurately arranged and adjusted in relation to the vertical centrality of the plumb-box, that the line of perpendicularity shall be common with the point of the bob and center of the wicktube. V

Attached to the exterior screw-threads on the flange b is a lantern-frame, or chimney, or holder, 0, consisting of the screw-threaded rings f ff, connected by the uprights g. The

lower ring, f, screws over the Ting of the V plumb-bob, and is provided with perforations h, serving as air-vents to promote combustion of the lamp, and in the lower ring are fixed inner studs, t, or'simil'ar means to serve as supports for the glass chimney. The upper ring, f, of the lantern-frame is perforated substantially as shown at k, for purposes of ventilation, and fitted with a screw-threaded cap or hood, E, to prevent falling water from reaching the flame. I

The letter D represents the glass or chimney of the lamp. This may be of any suitable transparent material, such as glass or mica. It finds a seat on the studs 03 in a lower ring of the lantern-frame, and extends .up into the npper ring, but not so far as to prevent the cap of the lantern from being properly ad j usted 'in place. The center of this cap is perforated to receive the cord or wire fromwhich the instrument is suspended. This perforation, the center of the wick-tube, and the point of the plumb-bob are on the same vertical line, in order that the point of suspension, the point of the flame, and the point of the plumb-bob shall register in practice.

The instrument can be suspended, as de scribed, from a tripod or other implement by means of a wire or other material.

It will be readily seen that my invention is peculiarly adapted for use in mining opera-- tions, and in like places wherein the sunslight cannot be admitted. I

By means of the lantern-frame, with glas or chimneys, Iobviate disturbance of the flame or current of air, obtaining a steady, clear flame, the point of which coincides with the point of suspension and point of the plumb-bob.

It is obvious that the cap of the lantern may be made integral therewith.

I reserve the right to vary the construction and arrangement of the parts without departing'from the spirit of the invention, and also to use any of the well-known lights now known.

What I claim as my invention, and desire to secure by LettersPatent, is

1. The plumb-bob herein described, consisting, essentially, ofthe bob A, cap B, lanter11-fran1e0,andcap or hood E, arranged and combined substantially as and for the purcombined as set forth. poses set forth.

2. As an improved article of manufacture, In testimony whereof I affix in y signature in the plumb-bob consisting, essentially, of the presence of two witnesses. bob A, having chamber a and screw-threaded annulus b, the cap B, with central wick-holder, Vitnesses: the lantern-frame G, the transparent chimney JOHN HEWSTON, J r.,

JOHN IlOACI-I.

D, and cap or hood E, the whole arranged and J. O. SALA. 

